The present invention relates generally to an improvement of an apparatus for reproducing an image on a recording medium by using multi-channel exposure beams, and more particularly, to an image data processing apparatus which generates dot data to control each exposure beams.
There has been known an apparatus which can reproduce an image, according to image data stored in a memory device, on the recording medium by controlling the multi-channel exposure beams.
In the conventional apparatus of this kind, the image data is stored in the memory device such as Magnetic Tape, wherein the image data is generally created by a CAD system and hence called a "CAD data". The apparatus has some converters which convert the CAD data into an object data. Namely the CAD data is converted into a runlength data by way of a vector data, and finally the runlength data is converted into a dot data by a multi dot data converter. The multi dot data converter consists of a plurality of conversion units involved in a memory circuit and a converting circuit, wherein the number of the conversion units corresponds to the number of the exposure beams. Then the dot data is used in controlling the multi-channel exposure beams.
Recently, it is required to increase the number of channels of the exposure beams in order to shorten the exposure time for reproducing an image.
The above-mentioned conventional apparatus, however, has disadvantages of increases in the cost of producing the apparatus and in the time to maintain the apparatus. This is because the number of components which constitute the apparatus, the time for producing and adjusting the apparatus are increased naturally in the conventional apparatus. If the number of components is increased, the number of conversion units also must be increased to control each exposure beam. For example, if forty-channel exposure beams are applied in the conventional apparatus, forty conversion units are necessary.